The present invention relates to electrical devices, such as a cordless power tools or battery chargers, which are configured to receive a removable battery pack.
Battery packs, especially those which are configured for use with hand-held power tools, are often removable to facilitate recharging and to permit continued use of the tool via multiple battery packs. So that the battery pack is securely fastened to the tool during use, the battery pack and tool cooperate to form latching means. For example, U.S. Pat. No. 5,213,913 describes latching members disposed on opposite sides of a battery pack for cooperating with latching shoulders within a tool handle.
Attaching such a battery pack requires only a minimal axial insertion force. However, releasing the tool is more complicated, since the user must grip around the pack so as to permit squeezing of the buttons found on opposite sides of battery pack while at the same time axially withdrawing the battery pack. This operation is awkward for some users, particularly those with small hands or weak grips, and can require extensive force especially for heavier battery packs that are even more securely fastened to the device housing. Such battery packs also tend to be larger than is desired in order to accommodate latching means which pivot along the external surface of the battery pack. It would be useful to have a battery pack that is more compact and which has a lock and release mechanism requiring less user effort.